Our invention relates to carburetors especially for two-cycle, low-horsepower engines, such as for model airplanes, for small powered equipment like chain saws, etc.
Such carburetor may be controlled by pivoting of a control arm, around the axis of the throat of the carburetor. It is an objective of our invention that the rpm of the engine be more nearly responsive to the degrees of pivoting of the control arm about that axis than has been the case in the past.
A tapered plug may be used in the throat of this type of carburetor to control air intake to the engine by moving into and out of the carburetor throat. It is an objective to provide a fuel supply tube central of said plug, extending along said axis, in which the downstream discharge end is more or less covered by the plug in order to meter less fuel when the plug admits less air and to meter more fuel when the plug admits more air. Further, it is an objective to provide on said discharge tube a full annular reduced diameter portion which flares from smaller diameter to larger diameter downstream of said throat so that as the plug moves downstream it covers a smaller and smaller annular fuel discharge area from fuel supply tube.
Another objective is to shape the parts in proximity to the fuel discharge area to act as baffles to resist pickup of fuel in air blowback from the engine.
Another objective is to locate the manually manipulated needle valve at the side of the carburetor housing away from the propeller so there will be less chance of the hand being struck by the propeller.